it 既然是形式主语,那么自然有一个真正的主语,那就是“to do this thing”,也就是说不要it这个形式主语的话可以理解成：To do this thing is important for me.
it可以在英语中是比较常见的形式主语比如：it takes me 2 hours to get there.
It cost me 300 dollors for my daughter's birthday...
It的用法还得自己多多看文章理解了.....
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